Liam Stanton, of Wakefield, walked free from Leeds Crown Court more than six months after being arrested on suspicion of theft.
He had been accused of stealing a shirt from Top Man in Wakefield – an allegation he always denied.
And the court entered a formal not guilty verdict in the case after the prosecution offered no evidence.
Liam, of the Lupset Estate, said: "I am so relieved it is over. I always knew I was totally innocent and now that has been confirmed in court. When I was arrested they told me to take a caution, to keep it out of the papers, but that would have meant I had a criminal record when I had done nothing wrong.
"I wanted to have my day in court, to go in front of a jury, so I could walk out of there a free man and without a stain on my character."
In the run up to being arrested, on November 2 last year, Liam's future looked bright. He was a promising young police community support officer and had hoped to go on to serve as a full time constable.
But he said he was angry with West Yorkshire Police over the way he was treated – anger which eventually led to him resigning.
He claims that as well as being handcuffed by arresting police officers, he was left in a cell for more than 12 hours.
And he alleged that a search team sealed off his bedroom and took away bags of clothes as "evidence".
Liam said: "I had to resign. I think they decided to make an example of me but they set themselves up for a fall because I knew I had done nothing wrong.
"My family were panicking when I was in that cell. They didn't know where I was, they were ringing hospitals, and I couldn't believe it when I heard they had taken bags of clothes away.
"My family said some of the clothes were in Top Man bags. Surely that showed I was a paying customer at the shop."
The 19-year-old said the months waiting for Wednesday's court appearance saw him sink into a depression, placing immense strain on both him and his family.
He added: "It was terrible for all of us. I ended up not going out, seeing my solicitor was like a social event for me, and when I was in a shop I was worrying if the staff were looking, wondering what I was up to.
"The worry is still with me, but I have been found not guilty now and that feels great. I am determined to move on."