Police Theft

I'm curious as to what can be done as far as police theft. What happened was I was arrested and while I was in custody my 3 rings were stolen. 1 was a breast milk ring from after I stopped feeding my daughter and the 2 other ones were my deceased mothers engagement and wedding rings. (Mind you my father had already passed and this happened only 3 weeks after my mother's passing) They were the single most sentimental and important thing I had left of both my parents. I'm in the DFW metroplex if that helps. I also have already spoken with the cheif of police and he did a month long investigation and he basically said he saw them on camera, then the next time my property bag was seen they weren't in there. They had me file with the city insurance but because I didn't have any sort of appraisal or anything done they offered me a measly $250 which was a slap in the face because of their sentimental value.