I WILL SAY A ROTUND YEP! HE IS CAPABLE OF SINING.
CONSIDER THE FOLLOWING EXAMPLES OF THIS LOVING GOD IN THE OLD TESTAMENT!
Beligerence and Ruthlessness of Jehovah:
Gen. 35:5, Ex. 14:14, 14:25-28, 15:3 and 17.16; Deut. 4:33-35, 7:21-24, 10:17-21, 11:25, 20:1-4, 20:16-17, 31:3, 32:21-26 and 32:39-42; Josh. 5:13-14, 10:25; 1st Sam. 2:25, 17:45-47; 2nd Sam. 22:25; 2nd Chr. 20:15-17; Neh 4:20; Psalms 18:34-40, 24:8 and 144:1; Isaiah 13:4, 31:4, 42:13 and 66:15-17; Jer 1:19, 21:5-12, 48:10, 50:25 and 51:11; Joel 2:10-11 and 3:10; Zech 8:10, 9:14-16 and 14:3; 2nd Cor. 5:11; and Heb. 10:31
Cannibalism - Threatened, Predicted, or Carried out by Jehovah
Lev. 26:29; 2nd Kings 6:27; Is. 49:26; Jer. 19:9; Lam. 2:20; Lam. 4:10; and Ezek. 5:10
Infants or Children killed, Suggested or Carried out by Jehovah
Lev. 26:22; Num 31:17; Deut. 3:6; 1 Sam. 15:3; 2nd Sam. 12:15-18; Ps. 137:8-9; Isa. 14:21, 13:18; Jer. 2:30, 15:7 and 18:21; Lam. 4:10; Ezek. 9:6; Hos. 2:4, 9:12 and 13:16
Innocent People Punished by Jehovah
Gen. 9:20-25, 20:18; Ex. 12:29-30, 20:5; Lev. 21:17-21; Deut. 5:9; 1st Sam. 3:11-14; 2nd Sam. 5:8; Job 1:1-19, 2:1-7, 30:20-31; and Isa. 14:21
Vindictiveness of Jehovah
Num. 11:31-34; Ps. 94:1; Isa. 34:1-15; Jer. 5:29-31, 9:9, 46:10, 50:13-15 and 51:36; Rom 12:19; Heb. 10:30-31
Commandments given, with extreme punishment for breaking by Jehovah
Ex. 31:14-15; Lev. 20:10-21, 21:9 and 24:10-16; Num. 5:12-27, 15:32-36; Deut 13:6-10, 13:12-16,17:2-6,21:18-21, 22:21; and Zech. 13:3
Hostility of Jehovah
Ps. 2:12, 6:1, 7:6, 7:11, 21:9, 27:9, 38:3, 47:2, 56:7, 59:13, 68:35, 69:24, 74:1-2, 76:12, 77:12, 77:9, 78:21, 78:31, 78:49-50, 78:58-66, 79:5, 80:4-6, 106:29, 106:32 and 106:40
Mercilessness of Jehovah
Deut. 7:2, 7:16 and 20:12-17; Ps. 1:4-9; Isa. 9:17-20; Jer. 20:16
Deception by Jehovah
1st Kings 22:23; 2nd Chr. 18-22; Is. 19:14, 66:4; Jer. 4:10, 18:11, 20:7, and 51:11; Ezek. 14:9 and 20:25-26
Dishonesty - Cheating, Stealing, and more, Often at Jehovahs Orders
Gen. 17:8, 25:29-34, 27:6-26, 30:37-43 and 34:6-31; Ex. 3:18-22; Deut. 3:7, 14:21 and 20:10-15; Josh. 24:13; Jud. 11:21-24; 1st Kings 22:20-23; 2nd Kings 8:10; 1st Chr. 5:21, 26:27; and 2nd Chr. 20:25
Evil Carried Out or Threatened by Jehovah
Jud. 2:15, 9:23; 1st Sam. 16:14-15, 18:10; 2nd Sam. 21:11, 24:15-16; 1st kings 14:10, 22:23; 2nd Kings 21:12-15; 2nd Chr. 18:22; Isa. 19:14, 31:2 and 45:7; Jer. 1:14-16, 11;11, 11:17, 11:23, 18:7. 18:11, 19:15, 21:9-12. 25:29, 32:42, 35:17, 36:3, 44:2, 44:11, 44:27-29, 45:5, and Amos 3:6
Slavery Ordered, Upheld, or practiced per Jehovah
Deut. 20:10-11 (enslavement ordered on large scale); Ex. 21:1-7, 21:20-21; Deut. 15:12, 15:16 and 15:17; 2nd Chr. 12:5-8
Vaingloriousness of Jehovah (Excessive Power or Vanity)
Gen 22:9-12 (forces Abraham to almost murder his son, Isaac, just to see if Abraham fears him), Ex. 9:15-16 (Kills people with pestilence just to show his power), 10:1-2; Jud. 7:2; Ezek. 6:14
Killings by Jehovah, with his help or under his command
Gen. 5:24, 7:21-23, 19:24-25, 38:7 and 38:10, Ex. 12:29-30, 32:25-28 (3,000 killed); Lev. 10:1-2; Num. 11:1, (Many burned to death by Jehovah), 14:26-37, 16:32-35, 16:44-49 (14,700 killed), 21:5-6, 25:1-9 (24,000 killed), 31:7-18 and 33:4; Deut. 2:20-21, 2: 30-34 and 3:3-7 (people of 60 cities and other towns all killed); Josh. 6:21-24, 8:25-28 (12,000 killed), 10:10-13, 10:28-42 and 11:6:14; Jud. 1:4 (10,000 killed), 3:29 (10,000 killed), 8:10 (120,000 killed), 11:32-33, 12:6 (42,000 killed), 18:27, 20:23-25 (18,000 killed), 20:35 (25,000 killed) and 20:48; 1st Sam. 6:19 (Jehovah kills 50,070), 15:1-8 (all Amalekites), 23:1-5, 25:39 (Jehovah murders Nabal), 27:7-11 (all Amalekites again), 30:1-2 and 30:8 & 30:17 (all Amalekites except for 400); 2nd Sam. 5:19-25, 6:6-7 (Uzzah killed by jehovah for steading the Ark), 8:1-5, 8:13 (18,000 killed), 10:18 (more than 40,000 killed), 12:14-18 (David infant child murdered by Jehovah), 23:10-12 and 24:15,(70,000 killed); 1st King 18:19&40 (450 prophets killed), 20:28-30 (100,000 killed); 2nd kings 1:10-12, 2:23-24 (42 children killed), 10:17-30, 17:25 (lions sent by Jehovah to kill people) and 19:35 (Angel of the Lord Kills 185,000); 1st Chr. 5:19-22, 10:13-14 (the Lord kills King Saul); 2 Chr. 13:15-18 (500,000 killed), 13:20 (the Lord murders Jeroboam), 14:8-15 (One Million Killed), 20:22-25, 25:11-12 (10,000 killed on two occasions = 20,000 killed), 28:5-8 (120,000 killed) and 36:15-17; Esther 9:9-13 (510 killed); Jer. 33:5; Lam. 2:1-22, 5:43; Ezek 9:5-10
Jealousy of Jehovah
Ex. 20:5, 34:14; Deut. 4:24, 5:9, 6:14-15 and 29:20; Ps. 79:5; Ezek. 16:38, 36:5-6 and 38:19; Nah. 1:2; Hab. 3:8; and Zech. 8:2
Promises Broken by Jehovah
Num. 10:9, wich was clearly broken (see supporting text), 14:34, 26:65 (confirms this breach - only two Israelites entered the promised Land). See also Acts 7:1-5
Repentance by Jehovah - Promised or Accomplished
Jehovah repented so much that according to Jer. 15:6 he once got tired of doing it!
Gen. 6:6-7; Ex. 32:14; Jud 2:18; 1st Sam. 15:10, 15:11 and 15:35; 2nd Sam. 24:15-16; Ps. 106:45; Jer. 18:8, 26:3, 26:19 and 42:10; Joel 2:13; Amos 7:3, 7:6; Jonah 3:10
1 Samuel 15:2-3, 7-8
"This is what the Lord says: Now go and smite Amalek, and utterly destroy all that they have; do not spare them, but kill both man and woman, infant and suckling, ox and sheep, camel and *** ....' 
And Saul ... utterly destroyed all the people with the edge of the sword."
All that amounts to an overuse of "utterly destroy". You would have thought that after Moses brought down the Ten Commandments (Exodus 20), with the explicit "Thou shalt not kill" (Exodus 20:13), there would be some kind of objection to killing thousands of people, including women and children. Let's face it - if anyone here today got a vision from God telling him/her to go kill an entire race of people, it's far more likely the person would be declared insane rather than that becoming acceptable justification for utterly destroying cities and tribes.
No Mercy
Deuteronomy 7:2 
2 And when the LORD thy God shall deliver them before thee; thou shalt smite them, and utterly destroy them; thou shalt make no covenant with them, nor shew mercy unto them:
Deutenomomy 20:13-14,16
13 When the LORD your God delivers it into your hand, put to the sword all the men in it. 
14 As for the women, the children, the livestock and everything else in the city, you may take these as plunder for yourselves. And you may use the plunder the LORD your God gives you from your enemies. 
16 However, in the cities of the nations the LORD your God is giving you as an inheritance, do not leave alive anything that breathes.
Judges 18:27
27 Then they took what Micah had made, and his priest, and went on to Laish, against a peaceful and unsuspecting people. They attacked them with the sword and burned down their city.
Sexism
1 Corinthians 11:7 - 9
7 A man ought not to cover his head, since he is the image and glory of God; but the woman is the glory of man.
8 For man did not come from woman, but woman from man;
9 neither was man created for woman, but woman for man.
1 Corinthians 14:34 - 35
34 women should remain silent in the churches. They are not allowed to speak, but must be in submission, as the Law says. 
35 If they want to inquire about something, they should ask their own husbands at home; for it is disgraceful for a woman to speak in the church.
Slavery
Joel 3:8 
8 And I will sell your sons and your daughters into the hand of the children of Judah, and they shall sell them to the Sabeans, to a people far off: for the LORD hath spoken (it).
SO AFTER CAREFUL CONSIDERATION OF THIS I WILL HAVE TO SAY:
God Atrocities in the Bible are such that they make Hitler, Stalin, and Pol Pot look like Mother Theresa of Calcutta.
I will have to say: YES, God is very capable of committing SIN according to the Holy Bible!
Maybe the God of the Bible is not the GOD that many of us has made him to be in our minds.
FOR many years I thought of GOD as incapable of any bad thing, but the Bible itself is a testimony that GOD is capable of pretty nasty things.
Maybe, just maybe, if this Good GOD that we have mad in our minds that eixst, is in fact ALL GOOD, then, it means that He is another type of God, but not the Bible ONE.
Can it be that the Old Testament God was (as some Christian Gnogstics, and People like Marcion, (condemned as Heretic by the Catholic Church) in the very early church had said:
THe God of the Old Testament was not really God, but a Demiurg, and Jesus was the Son of the real God, THe Most High GOD!, that came to earth to reveal the real father of all! a good, all benevolent father of Mercy!
I do not know that this will be the answer but it makes a whole lot of sense to me. At least much more than just plain regular classical christianity.
Is either this, or some other answer that I have not consider, or the whole thing is just all false, and God in fact do not exist!
Any input, comments and critics are welcomed. I myself will like to know the answer to this riddle. But, as for the evidence in the old Testament, for the most part, I will have to say YES! GOD is able to SIN, and SIN a lot.
I do not like the idea, and is very unfortunate, but do not take it with me! Take it with the Bible, if you want to defend it!
And NO! it does not make it right that God committed all this atrocities in the Old testament!
Might does not make RIGHT!!!!